How does Docky decide whether to show the options "Pin to dock" and "New window" or not on right-click?

Hi!

I'd like to pin a program to a dock, however this option is not available when I right-click the dock-entry. I tried to find the reason for that in the .desktop file, but I couldn't find a difference to other .desktop files.

How does Docky decide if the options "Pin to dock" and "New window" are available or not?

Here's the .desktop file:

[Desktop Entry]
Encoding=UTF-8
Name=Iceweasel
Name[bg]=Iceweasel
Name[ca]=Iceweasel
Name[cs]=Iceweasel
Name[el]=Iceweasel
Name[es]=Iceweasel
Name[fa]=Iceweasel
Name[fi]=Iceweasel
Name[fr]=Iceweasel
Name[hu]=Iceweasel
Name[it]=Iceweasel
Name[ja]=Iceweasel
Name[ko]=Iceweasel
Name[nb]=Iceweasel
Name[nl]=Iceweasel
Name[nn]=Iceweasel
Name[no]=Iceweasel
Name[pl]=Iceweasel
Name[pt]=Iceweasel
Name[pt_BR]=Iceweasel
Name[ru]=Iceweasel
Name[sk]=Iceweasel
Name[sv]=Iceweasel
Comment=Browse the World Wide Web
Comment[bg]=Сърфиране в Мрежата
Comment[ca]=Navegueu per el web
Comment[cs]=Prohlížení stránek World Wide Webu
Comment[de]=Im Internet surfen
Comment[el]=Περιηγηθείτε στον παγκόσμιο ιστό
Comment[es]=Navegue por la web
Comment[fa]=صفحات شبکه جهانی اینترنت را مرور نمایید
Comment[fi]=Selaa Internetin WWW-sivuja
Comment[fr]=Navigue sur Internet
Comment[hu]=A világháló böngészése
Comment[it]=Esplora il web
Comment[ja]=ウェブを閲覧します
Comment[ko]=웹을 돌아 다닙니다
Comment[nb]=Surf på nettet
Comment[nl]=Verken het internet
Comment[nn]=Surf på nettet
Comment[no]=Surf på nettet
Comment[pl]=Przeglądanie stron WWW
Comment[pt]=Navegue na Internet
Comment[pt_BR]=Navegue na Internet
Comment[ru]=Обозреватель Всемирной Паутины
Comment[sk]=Prehliadanie internetu
Comment[sv]=Surfa på webben
GenericName=Web Browser
GenericName[bg]=Интернет браузър
GenericName[ca]=Navegador web
GenericName[cs]=Webový prohlížeč
GenericName[el]=Περιηγητής ιστού
GenericName[es]=Navegador web
GenericName[fa]=مرورگر اینترنتی
GenericName[fi]=WWW-selain
GenericName[fr]=Navigateur Web
GenericName[hu]=Webböngésző
GenericName[it]=Browser Web
GenericName[ja]=ウェブ・ブラウザ
GenericName[ko]=웹 브라우저
GenericName[nb]=Nettleser
GenericName[nl]=Webbrowser
GenericName[nn]=Nettlesar
GenericName[no]=Nettleser
GenericName[pl]=Przeglądarka WWW
GenericName[pt]=Navegador Web
GenericName[pt_BR]=Navegador Web
GenericName[ru]=Интернет-браузер
GenericName[sk]=Internetový prehliadač
GenericName[sv]=Webbläsare
X-GNOME-FullName=Iceweasel Web Browser
X-GNOME-FullName[bg]=Интернет браузър (Iceweasel)
X-GNOME-FullName[ca]=Navegador web Iceweasel
X-GNOME-FullName[cs]=Iceweasel Webový prohlížeč
X-GNOME-FullName[el]=Περιηγήτης Ιστού Iceweasel
X-GNOME-FullName[es]=Navegador web Iceweasel
X-GNOME-FullName[fa]=مرورگر اینترنتی Iceweasel
X-GNOME-FullName[fi]=Iceweasel-selain
X-GNOME-FullName[fr]=Navigateur Web Iceweasel
X-GNOME-FullName[hu]=Iceweasel webböngésző
X-GNOME-FullName[it]=Iceweasel Browser Web
X-GNOME-FullName[ja]=Iceweasel ウェブ・ブラウザ
X-GNOME-FullName[ko]=Iceweasel 웹 브라우저
X-GNOME-FullName[nb]=Iceweasel Nettleser
X-GNOME-FullName[nl]=Iceweasel webbrowser
X-GNOME-FullName[nn]=Iceweasel Nettlesar
X-GNOME-FullName[no]=Iceweasel Nettleser
X-GNOME-FullName[pl]=Przeglądarka WWW Iceweasel
X-GNOME-FullName[pt]=Iceweasel Navegador Web
X-GNOME-FullName[pt_BR]=Navegador Web Iceweasel
X-GNOME-FullName[ru]=Интернет-браузер Iceweasel
X-GNOME-FullName[sk]=Internetový prehliadač Iceweasel
X-GNOME-FullName[sv]=Webbläsaren Iceweasel
Exec=iceweasel %u
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=iceweasel
Categories=Network;WebBrowser;
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/vnd.mozilla.xul+xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;
StartupWMClass=Firefox-bin
StartupNotify=true